Respuesta :

Answer:

Step-by-step explanation:

radius=4 as it is tangent to x-axis.

y co-ordinate of center is 4 so radius=4

eq. of circle is (x-2)²+(y-4)²=4²

or x²-4x+4+y²-8y+16=16

or x²+y²-4x-8y+4=0